How to get back into Starcraft 2 multiplayer? [closed]

Best suggestion i can give is play some games, if you are afraid of loosing ranked matches at start then play custom games that don't count towards your placement or custom games that are made for practicing certain aspects of the game like "Multitasking train" or Build order tester.

Other than that you should read up on changes and new tactics since you last played, trying all maps in the map pool might also be a good idea if you don't want to loose in the beginning and watch videos/streams of other players so you see what people do.

Just remember in the long run your are expected to loose about 50% of your matches as long as there is people that are better than you do to the way the matching system works.

To your 2nd question you can check that on your Quick Match screen, if your still got some kind of placement it will say "Play one match to be placed in a new division for this season." if not it will say "Complete a series of multiplayer matches to determine your initial league placement." and it will say how many games are remaning.

If you have missed an entire season then you will need to replay your initial 5 placement matches and you will be ranked based on your performance of those 5 games.

As far as how to get back into the competitiveness, that's a personal goal/attitude that one has to adopt. New games come out that distract a person (myself included). It's really how much you want to get involved into it. You have to find a reason to play and to be competitive.

It's really simple. Play the game.

There's no magical procedure that will re-increase your skills. If you feel rusty, and don't want to play ladder because of that, then play some custom games. Although you'll get matched against random players, so they might be way better or much worse than you.

Playing ladder game is still the best form of practice, because the matchmaking system will match you against players of roughly the same skill. Maybe you also have some friends around that are roughly at the same skill-level as you and you can practice against them.

Apart from playing the game, you can also go and watch some streams (like the ones on twitch.tv). It might give you a good idea what strategies are currently in use (the "meta-game"), so that you don't get surprised when playing ladder.